A Prospective Study Examining the Effect of Selected Topical and Systemic Drugs on Pruritus Grading System Score and STAT 6 Expression in Patients of Prurigo Nodularis

Background: Prurigo nodularis (PN) is a chronic dermatologic condition presenting as multiple papulonodular lesions occurring with intense pruritus. Though numerous agents (topical, systemic, phototherapy and biological drugs) have been tried, the outcomes are variable. Objectives: The aim of this study was to assess the role of topical and systemic therapies in primary PN by comparing the Pruritus Grading System (PGS) score at baseline and 1 month post-therapy. Materials and Methods: Of 86 diagnosed cases of PN, 49 cases of primary PN were clinically graded by Pruritus Grading System Score (PGSS), and assessed histopathologically by IHC staining (STAT-1, 3, and 6). Apart from topical agents, oral nortriptyline (mild grade), methotrexate (moderate grade) and thalidomide (severe grade) were administered, whereas doxepin was administered for itching. The PGSS was assessed after 1 month of therapy. Results: Among 49 patients of PN, the majority of patients showed a significant decrease in PGSS (P = <0.001) in 1 mont, which correlated with STAT-6 expression. The combination of different topical and oral agents resulted in a statistically significant change in severity, though individual drugs did not achieve statistically significant results. Conclusion: A combination of selected oral and topical agents can effectively control the severity of PN within one month, and this was found to correlate with STAT 6 expression.